I'm interested to see what others are carrying. For me, a knife is one of my most important tools so it has to meet specific criteria. First, it has to have a blade around 3" (excellent size to use for many chores); a good grade of stainless steel; locking blade; single hand opening. With my knife, weight is a secondary concern. That said, I have carried a Ka-Bar Dozier Folding Hunter. I use it daily for various chores and have grown rather fond of it (especially for it's low price).

I've had the chance to examine the required gear of various stage racers (Marathon des Sables) and adventure racers and have been amazed by some of the useless blades people carry and plan on not using (like a half razor blade). Light? Yep. Useful in an emergency? Nope.

I love my Gerber Ultralight LST. It's .6 ounces and has a single blade that I find is great for everything I need. I attach a short lanyard so it doesn't get lost. I have a Microlight LST too that I use for shorter solo trips but the blace is a little small for cheese or bagels.

I use a knife for cutting food, prepping bandages/moleskin, and misc. other things. I used to carry a big ol' Victornox but here's why I don't carry that type of knife anymore:

The Swiss Army One Handed Trekker is a One-handed Serrated Locking Blade knife. (single blade- good!)• Large Locking-Screwdriver (never used a screwdriver in the field)• Bottle opener (no bottles to open)• Phillips Screwdriver (nothing to tighten)• Can opener (no cans for miles and miles)• Small screwdriver (ditto)• Reamer (this can be helpful but I used it very rarely)• Key ring (not needed)• Toothpick, Tweezers (I use my small, sharp Gerber blade)• Scissors (use the blade)• Wood Saw (if the piece of wood is this small, you can usually break it by hand or can kick it with a foot. I tried my old one a few times but found it a waste of time. However, if someone wanted clean cuts of small wood such as for a Bushbuddy stove, it might be useful, but I still doubt it.)

I don't like really short knives as I find a lot of cheese and salami can get stuck where the blade joins the handle. And if you are going fishing, a knife with a reasonably long blade is really essential. So I use an Opinel knife. These are the lightest knives I know of for their blade length. They are also quite cheap and come in many different lengths. I don't know their weights but they are very light.

And while I am rummaging through my little stuff trimming weight... what about a little plastic trail whistle? is it really a needed pack item... honestly around her(southeast) I wouldn't mind being "lost" for a few days.

If you want a longer blade for food prep, etc, I would second the Opinel folding knife. They are cheap and work well. I would also recommend the significantly more expensive Benchmade 530.

Is a saw necessary? The short answer is no, unless you are planning to be building a shelter, in which case you are better off with a wire saw and a fixed blade knife or hatchet that has a good swing weight. Only when I am in SERIOUS back county (Canadian rockies, etc) would I bother. Since all my backpacking in the last four years has been in the lower 48 states, I haven't brought my survival knife backpacking trip in a while. As far as survival knives go, I would recommend the Fallkniven F1 or if you have a lot of spare cash, the Chris Reeve Aviator.

Most of the time the only knife I take is the knife that is always in my pocket, a Victorininox Rambler which is a lot like the tiny "Classic" except that it has a small philips head blade / bottle opener. The blade is adequate (though a bit short) for the food prep I do, I can cut through light rope when needed, the scissors are easier to use than a blade when trimming duct or other first aid pads / tape, I can manage my nails using the scissors and nail file, and the small flat head and Phillips head screw drivers have been useful when I need to tighten up various items.

I decided last year to finally replace my 20 year old classic SAK and spent a lot of time thinking about this question. I wanted a locking blade, since unlocked blades can be dangerous. I ended up picking the one handed trekker myself. It is not the UL option, but for an all around knife, it can be great choice.

The blade is long and very substantial, and the serrations on the end are in the right place, with the flat blade close in. The only thing I don't like about the knife is the chisel grind, which is upside down when I use my left hand.

I carry a knife mainly for survival and emergencies, so I do consider the saw essential. A SAK saw is very useful for cutting wood if you are building a fire. You can notch sticks otherwise too thick to break. In an emergency, a saw would also let you cut tough green wood sticks 1-2" thick for a splint or crutch or ski pole or to fix a snowshoe, etc. The longer the saw the better, and so the added length of the OHT makes the saw even more useful.

The locking flat blade screwdriver may not be needed hiking, but it is very substantial, and would be good for prying and leveraging. I agree that I don't need a bottle opener on the trail, but wouldn't rule out opening something back at the car.

I wanted a phillips since my ski bindings are phillips, and I can't rule out running into a screw on a stove or something. I also like having an awl, since there is really no other good way to punch a hole into something like tough nylon for a field repair of a pack strap, etc.

I have several multi tools that I like too, but I can't justify the weight of pliers unless I was fishing (or maybe skiing, still haven't decided that one yet). But for a SAK, the OHT is perfect for me.

For a small ultralight knife I like the Spyderco Jester. It's almost identical to the ladybug, except it has a serrated finger rest at the top forward part of the blade that allows you to place your forefinger on it. The ergonomics are really excellent for such a small knife. It has a locking blade and weighs 0.6 oz

I know Cabela's carries the Benchmade Griptillian series in D2 tool steel. That's a great steel in a pretty classic design but at 3oz. even the mini isn't ultralight. Also, I believe A.G.Russell's carries several slipjoint (non-locking) knives in carbon steels.

I carry a simple razor blade, which is enough for me as I only need it to slice food packacking open and to repair gear on the trail. But half a razor blade sounds even better to me, I gotta try that. While it might make sense to carry a real knife for emergencies in the wilderness, the Alps are really far from beeing "wild", the next hut is never further away than a 4-5h walk. I don't feel like having to carry a lot of emergency items except a small first aid kit and a whistle.